筋すじ金がね

noun

metal reinforcement; reinforcing bar; stiffener

Refers to a metal bar, rod, or wire used to strengthen concrete, frameworks, or structures. Also used figuratively to describe a person of firm principles or strong will.

• この建たて物ものの柱はしらには筋すじ金がねが入はいっている。

  The pillars of this building have metal reinforcements inside.

• 彼かれは筋すじ金がね入いりの保ほ守しゅ派はだ。

  He is a dyed-in-the-wool conservative.